CHAPTER VI. 



THE MILLER'S THUMB, OR BULLHEAD. 



Miller's Thumb or Bullhead (Coitus gobio) is one of the only two 

 representatives of the family of fishes with ' ' hard cheeks ' ' in British 

 -waters. The interesting little stickleback, to which I shall refer in 

 -the succeeding chapter, is the other. The Miller's Thumb is somewhat 

 like the gurnard, and although its scientific name signifies " a large 

 headed gudgeon," I fail to perceive the slightest similarity between it 

 ~and the gudgeon. The broad head, the disposition of the fins, and their 

 spines, and its voraciousness, all and severally indicate its connection 

 with the percidce family. The principal structural distinction consists in 

 the suborbital bone being more or less extended over the cheek, and 

 connected with the gill cover. Its scientific position is thus indicated : 

 Series 1, bony fishes ; order 1, ancanthopterygii (fishes with spined fins) ; 

 family, "with hard cheeks"; genus, Cottus (from Kotte, the head 

 {jrreek). It is colloquially termed in some parts of England, " Tommy 

 Log-ge." Cottus golio has teeth in both jaws (although Walton says 

 not), spines on the gill covers, gills with six rays, two back fins, and no 

 scales. It spawns from about April to June, and produces a large number 

 of ova. It makes its nest in not so elaborate a manner as the stickleback, 

 but yet with a sort of method. Boring with its flat- spined head by the 

 side of a large stone it gradually excavates an opening. The spot is 

 selected for advantages of stream. Having accomplished its purpose, 

 the female deposits the eggs, and is quickly followed by the male in the 

 act of impregnation. This effected, the male covers up the ova and 

 keeps guard until the young fish not only are born but arrive at an age 

 to look after themselves. Like the female stickleback the maternal 

 parent is of a very pronounced cannibalistic turn of mind, and it is often, 

 notwithstanding careful guard, impossible for the fry to escape the hungry 



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